Electrical connector



Feb. 20, 1962 'r. STEPOWAY 3,022,481

ELECTRICAL CONNECTOR Filed Feb. 26, 1960 20 v '8 INVENTOR THEODORE STEPO WAY ATTORNEY United States Patent 3,022,481 ELECTRICAL CONNECTORTheodore Stepoway, 713 Ranier Circle, Garland, Tex. Filed Feb. 26, 1960,Ser. No. 11,216 4 Claims. (Cl. 339-75) This invention relates to anelectrical connector eminently suited for establishing circuits inconjunction with printed circuit cards.

It is important in establishing electrical connections with printedcircuit cards and boards that the contacts be firm regardless of thepresence of thickness variations in the support or the conductorsthemselves. It is also desirable that the connections be established andbroken quickly when needed. It is quite necessary that circuitconditions be maintained without accidental interruption.

All of these results have been achieved in accordance with the presentinvention which includes among its objects the provision of anelectrical connector comprising a frame providing a bearing surface fora conductive strip, the frame supporting a resilient contact elementspaced relatively to the conductive strip, a cam having a surface ofelectrical insulation movably supported with respect to the contactelement for urging the contact element towards the conductive strip,means for moving the cam with respect to the conductive strip, anddetent means for maintaining the cam in adjusted position. The cam ispreferably rotatable and may be composed entirely of electricalinsulation. A ratchet and pawl mechanism is preferably provided forlatching the cam in any of a plurality of adjusted positions, and in apreferred form of the invention, the bearing surface supports anelectrical conductive strip which is electrically connected to theresilient contact element and to such additional conductors as may berequired by the functions desired.

In a preferred form of the invention there are a plurality ofresiliently mounted contact elements carried by the frame spaced fromthe conductive strips and from one another and the cam simultaneouslyengages these elements for urging them toward the conductive strips forengagement with a plurality of conductors on an intervening printedcircuit card and the like. The plural contact elements may be supportedin substantial alignment with the conductive strips and may assume theform of leaf springs. Where a plurality of such contact elements arepresent, the bearing surface may support spaced electrical conductivestrips opposite such elements respectively.

A more complete understanding of the invention will follow from adescription of the accompanying drawings wherein:

FIG. 1 is a perspective view of an electrical connector conforming tothe present invention;

FIG. 2 is a front elevation of the connector shown in FIG. 1;

FIG. 3 is a sectional elevation taken along line 3-3 of FIG. 2;

FIG. 4 is an elevation of the right end of the connector as viewed inFIG. 2;

FIG. 5 is a fragmentary plan view of the connector;

FIG. 6 is a fragmentary perspective view depicting the detent mechanismcontemplated; and

FIG. 7 is a sectional elevation, similar to FIG. 3, showing anotherarrangement of terminals.

A frame or housing 10 of electrical non-conductive material is providedwith an internal chamber 12 providing a bottom wall 14 defining abearing surface. A plurality of conductive strips 16 are arranged inspaced relationship along the bearing surface, and corresponding andsuper-imposed relative to each of these conductive strips there is showna resilient leaf spring contact element 18. As shown in FIG. 3, theseconductive strips and contact elements may be provided with enlargements20 about which the insulating resinous or comparable thermoplasticmaterial constituting the frame or housing may be molded. As alsodepicted in FIG. 3, ends 22 of the conductive strips and contactelements may project through the rear wall of the frame or housing tofacilitate the attachment of leads by means of solder or otherconventional materials. The internal chamber 12 also provides an upperwall or bearing surface 24 for engagement with the contact elementsalong portions of their lengths to limit their upward movement withrespect to the conductive strips 16, each contact element 18 having afree end projecting beyond the bearing surface 24 which overlies thecorresponding conductive strip 16 in spaced relation thereto. A shaft 26is suitably journaled at the ends of the frame or housing 10 and carriesan elongated cam 28 of nonconductive material which is resilient anddeformable so as to yield whenever bodies of diifering thicknesses areinterposed between the conductive strips and contact elements betweenwhich the conductors of a printed circuit board, tape, or card areengaged. The cam 28, when rotated, is adapted to contact the free endsof the contact elements 18.

As illustrated in FIG. 7, the ends 22 of the conductive strips andcontact elements may be mutually insulated so as to provide independentelectrical paths to printed circuits on opposite sides of the board ortape employed.

Whereas nylon has been very satisfactory as the cam material for anumber of applications of the present invention, other materialsdisplaying the properties of resilience and deformability in conjunctionwith their ability to insulate electrically are contemplated.

The shaft 26 projects beyond one end of the frame or housing to receivea combined knob and ratchet wheel 30. A sliding pawl 32 is resilientlyurged towards the ratchet wheel by means of a leaf spring 34 suitablysupported, together with the pawl, in an extension 36 formed at one endof the housing. As shown in FIG. 6, the pawl is in engagement wtih theratchet wheel 30. When it is desired to retract the pawl from the teethof the ratchet wheel, the operator will engage the thumb piece 38carried by the pawl and move it away from the teeth of the ratchet wheelagainst the force of the leaf spring 34.

The contact elements and conductive strips may be formed with lowresistance contacts 40 of beryllium copper, silver, gold or any othermaterial required by a particular installation.

When a printed circuit card, for example, is to be inserted in theconnector, the cam 28 will be placed in an elevated position, as thatshown in FIG. 3, so that the leaf spring contact elements 18 will beraised by their own resilience to admit the card between them and theiropposed conductive strips 16. With the card thus positioned, thecombined knob and ratchet wheel 30 will be rotated to cause the cam 28to urge the free ends of the contact elements 18 into firm engagementwith the cardcarried conductors, the pawl 32 engaging the ratchet teethunder the force of the leaf spring 34 to maintain any adjusted position.By virtue of the resilience and deforrnability of the cam coupled withthe resilience of the contact elements 18 themselves, it will be clearthat good contact will occur even where the dimensions of the cards andtheir printed circuits vary. To release the card, it is merely necessarythat the pawl 32 be retracted against the force of its leaf spring 34,whereupon the card can be withdrawn.

Whereas only one form of the present invention has been described withreference to the accompanying drawings, such variations as will besuggested to those skilled in the art are contemplated by the appendedclaims.

I claim:

1. An electrical connector comprising a frame of electricalnon-conductive material providing a chamber adapted to receive a printedcircuit board or the like, said chamber having opposed top and bottomwalls forming bearing surfaces and having a back wall, at least oneelectrical conductive strip secured in place along one of said bearingsurfaces and at least one corresponding resilient contact element alongthe other of said bearing surfaces, supporting means for one end of saidresilient contact element, the inherent resilience of said contactelement urging a portion thereof, adjacent said supporting means,against said other bearing surface, said resilient contact elementhaving a free end projecting beyond said other bearing surface andoverlying, in spaced relation, said corresponding conductive strip,whereby the free end can be flexed toward and away from said conductivestrip, a cam having a surface portion of progressively varying radiusmovably supported with respect to and engageable with the free end ofsaid contact element for urging said element in a direction toward saidelectrical conductive strip, and means for moving said cam.

2. An electrical connector as defined in claim 1, where:- in said framesupports a ratchet and pawl mechanism for latching said cam in adjustedposition.

3. An electrical connector as defined in claim 1, in which said cam iscomposed of a readily resilient and deformable material.

4. An electrical conductor as defined in claim 1, in which said cam iscomposed of nylon.

References Cited in the file of this patent UNITED STATES PATENTS837,501 Plinos Dec. 4, 1906 2,730,683 Ayres et a1. Jan. 10, 19562,923,911 Demurjian Feb. 2, 1960 FOREIGN PATENTS 216,045 SwitzerlandNov. 17, 1941 629,734 Great Britain Sept. 27, 1949

